Directed self-assembly of nanoparticles with polymeric and/or oligomeric ligands

Abstract

In one embodiment, a method includes: depositing a plurality of nanoparticles on a substrate; and forming a monolayer of the nanoparticles on the substrate via self-assembly, where each of the nanoparticles comprises a nanoparticle core grafted to one or more oligomers and/or polymers, where each of the polymers and/or oligomers includes at least a first functional group configured to bind to the nanoparticles. In another embodiment, a method includes: depositing a plurality of nanoparticles on a substrate; and forming a monolayer of the nanoparticles on the substrate via self-assembly, where the nanoparticles each comprise a nanoparticle core grafted to one or more oligomers and/or polymers, each of the polymers and/or oligomers including a first terminal functional group configured to bind to the nanoparticles, and an optional second terminal functional group configured to bind to the substrate, where the substrate comprises guiding features configured to direct the self-assembly of the nanoparticles.

What is claimed is: 
     
         1 . A method, comprising:
 depositing a plurality of nanoparticles on a substrate; and   forming a monolayer of the nanoparticles on the substrate via self-assembly,   wherein each of the nanoparticles comprises a nanoparticle core grafted to one or more oligomers and/or polymers,   wherein each of the polymers and/or oligomers includes at least a first functional group configured to bind to the nanoparticles.   
     
     
         2 . The method as recited in  claim 1 , wherein each nanoparticle core independently comprises a material selected from a group consisting of: a metal, a dielectric, and a semiconductor. 
     
     
         3 . The method as recited in  claim 1 , wherein each nanoparticle core has a diameter in a range between about 1 nm to about 15 nm, and wherein a pitch between adjacent nanoparticle cores is in a range between about 5 to about 20 nm. 
     
     
         4 . The method as recited in  claim 1 , wherein each of the polymers and/or oligomers has an average molecular weight between about 0.5 kDa to about 10 kDa. 
     
     
         5 . The method as recited in  claim 1 , wherein each of the polymers and/or oligomers is independently selected from a group consisting of: polystyrene, polymethyl methacrylate, polydimethyl siloxane, polyvinyl pyridine, polyferrocenyldimethylsilane, polyethylene oxide, polylactic acid, and polytrimethylsylilstyrene. 
     
     
         6 . The method as recited in  claim 1 , wherein the monolayer of the nanoparticles formed on the substrate has a nanoparticle surface coverage between about 80% to about 120%. 
     
     
         7 . The method as recited in  claim 1 , further comprising annealing the nanoparticles that are deposited on the substrate to facilitate the self-assembly of the nanoparticles, wherein the annealing occurs prior to a bonding of the polymers and/or oligomers to the substrate. 
     
     
         8 . The method as recited in  claim 1 , wherein each of the polymers and/or oligomers further includes a second functional group configured to bind to the substrate, wherein the second functional group of each of the polymers and/or oligomers is further configured not to bind to the nanoparticle, and wherein the second functional group of each of the polymers and/or oligomers is further configured not to bind to the second terminal functional group of another polymer and/or oligomer. 
     
     
         9 . The method as recited in  claim 8 , wherein the second functional group of each of the polymers and/or oligomers is independently selected from a group consisting of: a hydroxyl, a carboxyl, and an amine. 
     
     
         10 . The method as recited in  claim 8 , further comprising bonding the polymers and/or oligomers grafted to the nanoparticles to the substrate, wherein the bonding of the polymers and/or oligomers to the substrate includes providing an activation treatment to enable bonding between the second functional group of each of the polymers and/or oligomers and the substrate, wherein the activation treatment includes at least one of: a heat treatment, an optical treatment, and a chemical treatment. 
     
     
         11 . The method as recited in  claim 10 , wherein after the bonding of the polymers and/or the oligomers to the substrate, the method further comprises rinsing the substrate to remove any material not bonded to the substrate. 
     
     
         12 . A method, comprising:
 depositing a plurality of nanoparticles on a substrate; and   forming a monolayer of the nanoparticles on the substrate via self-assembly,   wherein the nanoparticles each comprise a nanoparticle core grafted to one or more oligomers and/or polymers, each of the polymers and/or oligomers including a first terminal functional group configured to bind to the nanoparticles, and an optional second terminal functional group configured to bind to the substrate,   wherein the substrate comprises a plurality of guiding features configured to direct the self-assembly of the nanoparticles.   
     
     
         13 . The method as recited in  claim 12 , wherein the guiding features are positioned at interstitial sites between the nanoparticles. 
     
     
         14 . The method as recited in  claim 12 , wherein a pitch between adjacent guiding features is about equal to or greater than a pitch between adjacent nanoparticle cores, wherein the pitch between adjacent nanoparticle cores is in a range between about 5 to about 20 nm. 
     
     
         15 . The method as recited in  claim 14 , wherein the pitch between adjacent guiding features (L s ) is represented by: L s ≈nL 0 , where n is an integer equal or larger than 1, and L 0  is the pitch between adjacent nanoparticle cores. 
     
     
         16 . The method as recited in  claim 15 , wherein the pitch between adjacent guiding features is about equal to or greater than a lattice plane spacing associated with the monolayer of the nanoparticles. 
     
     
         17 . The method as recited in  claim 12 , wherein a width of each of the guiding features is about equal to or less than an interparticle distance between adjacent nanoparticle cores. 
     
     
         18 . The method as recited in  claim 12 , wherein a height of each of the guiding features is about equal to or less than a thickness of the monolayer of the nanoparticles. 
     
     
         19 . The method as recited in  claim 12 , wherein the guiding features comprise at least one of: an array of pillars, an array of stripes, an array of spheres, an array of holes, an array of trenches, an array of squares, and an array of triangles. 
     
     
         20 . The method as recited in  claim 12 , wherein there is a chemical and/or topographical contrast between the guiding features and regions therebetween. 
     
     
         21 . A method, comprising:
 depositing a plurality of nanoparticles onto a substrate;   forming a monolayer of the nanoparticles on the substrate via self-assembly; and   defining a plurality of nucleation regions and a plurality of non-nucleation regions in the monolayer of the nanoparticles,   wherein the nanoparticles each comprise a nanoparticle core grafted to one or more oligomers and/or polymers, each of the polymers and/or oligomers including: a first functional group configured to bind to the nanoparticles, and an optional second functional group configured to bind to the substrate.   
     
     
         22 . The method as recited in  claim 21 , wherein the defining of the plurality of nucleation regions and the plurality of non-nucleation regions in the monolayer of the nanoparticles comprises removing a portion of the polymers and/or oligomers present between each of the nanoparticles. 
     
     
         23 . The method as recited in  claim 22 , wherein the method further comprises etching a portion of the substrate between the nanoparticles for pattern transfer into the substrate, wherein the substrate includes at least one of a metal, a dielectric material and a semiconductor material. 
     
     
         24 . The method as recited in  claim 23 , wherein the method further comprises depositing a crystalline layer above the monolayer of the nanoparticles. 
     
     
         25 . The method as recited in  claim 21 , wherein the method further comprises:
 depositing a protective layer above the monolayer of the nanoparticles after the polymers and/or oligomer therebetween are substantially removed;   etching a portion of the substrate between the nanoparticles;   removing the monolayer of the nanoparticles; and   depositing a crystalline layer above the substrate,   wherein the substrate has a crystallographic orientation substantially along an axis perpendicular to an upper surface of the substrate.